High-voltage circuit breaker device for intelligent power grid

Abstract

The invention belongs to the field of electric power, and particularly relates to a high-voltage circuit breaker device for an intelligent power grid, which comprises a circuit breaker body, an arc extinguish chamber is arranged in the circuit breaker body, an arc extinguish grid assembly is arranged in the arc extinguish chamber, and the arc extinguish grid assembly comprises a shell and a plurality of arc extinguish grid sheets mounted in the shell. The arc extinguishing grid assembly further comprises a first piezoelectric ceramic piece and a second piezoelectric ceramic piece, the first piezoelectric ceramic piece and the second piezoelectric ceramic piece are installed on the two sides of the shell respectively, the first piezoelectric ceramic piece and the second piezoelectric ceramic piece are both fixedly connected with the outer side wall of the shell, and the first piezoelectric ceramic piece and the second piezoelectric ceramic piece are both parallel to the arc extinguishing grid piece. According to the low-voltage circuit breaker, the arc extinguish chamber in an existing low-voltage circuit breaker is optimally designed, the arc extinguish grid pieces are improved, and the first piezoelectric ceramic piece and the second piezoelectric ceramic piece are additionally arranged, so that the arc extinguish effect can be remarkably improved, zero flashover can be achieved, the arc extinguish effect of the arc extinguish chamber is good, the size of the arc extinguish chamber does not need to be multiplied, and practicability is high.

Description

Technical Field

[0001] The present invention belongs to the field of electric power technology, and in particular relates to a high-voltage circuit breaker device for a smart grid. Background Art

[0002] A circuit breaker is a switch device that can close, carry and disconnect current under normal circuit conditions and close, carry and disconnect current under abnormal circuit conditions within a specified time. Circuit breakers are divided into high-voltage circuit breakers and low-voltage circuit breakers according to their scope of use. The boundary between high and low voltage is relatively vague, and those above 3kV are generally called high-voltage electrical appliances.

[0003] A circuit breaker is generally composed of a contact system, an arc extinguishing system, an operating mechanism, a release, a casing, etc.

[0004] When short-circuited, the magnetic field generated by the large current (generally 10 to 12 times) overcomes the reaction spring, the release pulls the operating mechanism to operate, and the switch trips instantly. When overloaded, the current becomes larger, the heat increases, and the bimetallic strip deforms to a certain extent to drive the mechanism to operate (the larger the current, the shorter the operating time).

[0005] The function of the circuit breaker is to cut off and connect the load circuit, as well as to cut off the fault circuit, to prevent the accident from expanding and to ensure safe operation. The high-voltage circuit breaker has to break the arc of 1500V and the current of 1500-2000A. These arcs can be extended to 2m and still continue to burn. Therefore, arc extinguishing is a problem that must be solved by high-voltage circuit breakers.

[0006] Arc extinguishing grid is one of the basic methods to extinguish arc. Arc extinguishing grid is generally made of steel sheet. In AC low-voltage switchgear, when an arc is generated between contacts, the arc is pulled into the arc extinguishing grid under the contraction force of magnetic lines of force. A long arc is divided into multiple short arcs. When the AC current passes through zero, all short arcs are extinguished at the same time. Due to the near-cathode effect, a starting dielectric strength of 150-250V immediately appears near the cathode of each short arc. As long as the sum of the starting dielectric strengths of all series short arcs is greater than the applied voltage between the contacts, the arc will not reignite.

[0007] At present, arc extinguishing grids are mainly used in low-voltage circuit breakers. If used in high-voltage circuit breakers, the volume of the arc extinguishing chamber is very large and its application is limited. Compared with other arc extinguishing methods (such as chemical arc extinguishing), the use of arc extinguishing grids to extinguish arcs is more economical and has high stability.

[0008] Based on this, the present invention is proposed. Summary of the invention

[0009] The object of the present invention is to provide a high voltage circuit breaker device for a smart grid to solve the above-mentioned problems.

[0010] A high-voltage circuit breaker device for a smart grid comprises a circuit breaker body, wherein a lower terminal is arranged at the lower part of the circuit breaker body, an arc extinguishing chamber is arranged inside the circuit breaker body, an arc extinguishing grid assembly is arranged inside the arc extinguishing chamber, the arc extinguishing grid assembly comprises a shell, and a plurality of arc extinguishing grids installed in the shell, wherein the arc extinguishing grids are arranged along the length direction of the shell, the arc extinguishing grid assembly further comprises a piezoelectric ceramic sheet 1 and a piezoelectric ceramic sheet 2, wherein the piezoelectric ceramic sheet 1 and the piezoelectric ceramic sheet 2 are respectively installed on both sides of the shell, the piezoelectric ceramic sheet 1 and the piezoelectric ceramic sheet 2 are both fixedly connected to the outer side wall of the shell, and the piezoelectric ceramic sheet 1 and the piezoelectric ceramic sheet 2 are both arranged parallel to the arc extinguishing grid.

[0011] As a further improvement, the arc extinguishing grid is a U-shaped structure.

[0012] A further improvement is that semi-elliptical grooves are provided on both the front and rear sides of the arc-extinguishing grid, and the portion of the arc-extinguishing grid located between the two semi-elliptical grooves is a gradient section; a T-shaped antimony sheet is provided in the semi-elliptical groove, and the T-shaped antimony sheet includes an antimony bar connected to the notch of the semi-elliptical groove as a whole, and an antimony block with a trapezoidal structure, the lower bottom of the antimony block is connected to the antimony bar as a whole, and the upper bottom of the antimony block is connected to the gradient section as a whole; a first hollow hole and a second hollow hole are formed between the semi-elliptical groove and the T-shaped antimony sheet, and the first hollow hole and the second hollow hole are respectively located on both sides of the antimony block.

[0013] As a further improvement, in a single arc-extinguishing grid, the first hollow hole outside the first semi-elliptical groove is arranged opposite to the second hollow hole outside the second semi-elliptical groove, and the second hollow hole outside the first semi-elliptical groove is arranged opposite to the first hollow hole outside the second semi-elliptical groove.

[0014] As a further improvement, the area of ​​the first hollow hole is not equal to the area of ​​the second hollow hole.

[0015] As a further improvement, the ratio of the area of ​​the first hollow hole to the area of ​​the second hollow hole is x, 1.5≤x≤2.

[0016] As a further improvement, the area of ​​the piezoelectric ceramic sheet one is equal to the area of ​​the piezoelectric ceramic sheet two and their values ​​are both y, the orthographic projection of the piezoelectric ceramic sheet one and the orthographic projection of the piezoelectric ceramic sheet two are partially overlapped, and the overlapping area between the orthographic projection of the piezoelectric ceramic sheet one and the orthographic projection of the piezoelectric ceramic sheet two is z, 0.3≤z / y≤0.5.

[0017] As a further improvement, the resonance frequency of the first piezoelectric ceramic sheet is not equal to the resonance frequency of the second piezoelectric ceramic sheet.

[0018] As a further improvement, the resonance frequency of the piezoelectric ceramic piece 1 is 10.5 MHz, and the resonance frequency of the piezoelectric ceramic piece 2 is 23.2 MHz.

[0019] As a further improvement, a shock absorbing layer is filled between the first piezoelectric ceramic sheet and the second piezoelectric ceramic sheet and the circuit breaker body.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The high-voltage circuit breaker device for smart grid described in the present invention optimizes the design of the arc extinguishing chamber in the existing low-voltage circuit breaker, improves the arc extinguishing grid and adds piezoelectric ceramic sheet one and piezoelectric ceramic sheet two, so that not only the arc extinguishing effect can be significantly improved, but also zero arcing can be achieved. The arc extinguishing effect of the arc extinguishing chamber is good, and there is no need to increase the volume of the arc extinguishing chamber by multiples, so the practicability is strong. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a structural schematic diagram of a high-voltage circuit breaker device for a smart grid according to the present invention;

[0023] Figure 2 It is a structural schematic diagram of the arc extinguishing chamber of the present invention;

[0024] Figure 3 It is a schematic diagram of the structure of the arc extinguishing grid of the present invention. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below through specific embodiments in conjunction with the accompanying drawings.

[0026] In the description of the present invention, it should be noted that, unless otherwise specified, "multiple" means two or more than two; the directions or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0027] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] Example 1

[0029] like Figures 1 to 3 As shown, a high-voltage circuit breaker device for a smart grid includes a circuit breaker body 10, a lower terminal 11 is provided at the lower portion of the circuit breaker body 10, an arc extinguishing chamber is provided inside the circuit breaker body 10, an arc extinguishing grid assembly is provided in the arc extinguishing chamber, the arc extinguishing grid assembly includes a shell 21, a plurality of arc extinguishing grids 22 installed in the shell 21, the arc extinguishing grids 22 are arranged along the length direction of the shell 21, the arc extinguishing grid assembly also includes a piezoelectric ceramic sheet 1 51 and a piezoelectric ceramic sheet 2 52, the piezoelectric ceramic sheet 1 51 and the piezoelectric ceramic sheet 2 52 are respectively installed on both sides of the shell 21, the piezoelectric ceramic sheet 1 51 and the piezoelectric ceramic sheet 2 52 are both fixedly connected to the outer side wall of the shell 21, and the piezoelectric ceramic sheet 1 51 and the piezoelectric ceramic sheet 2 52 are both arranged parallel to the arc extinguishing grid 22.

[0030] The arc extinguishing grid 22 is a U-shaped structure.

[0031] Semi-elliptical grooves 221 are provided on both the front and rear sides of the arc-extinguishing grid 22, and the portion of the arc-extinguishing grid 22 located between the two semi-elliptical grooves 221 is a gradient section 222; a T-shaped antimony sheet 30 is provided in the semi-elliptical groove 221, and the T-shaped antimony sheet 30 includes an antimony bar 31 connected to the notch of the semi-elliptical groove 221 as a whole, and an antimony block 32 with a trapezoidal structure, the lower bottom of the antimony block 32 is connected to the antimony bar 31 as a whole, and the upper bottom of the antimony block 32 is connected to the gradient section 222 as a whole; a first hollow hole 33 and a second hollow hole 34 are formed between the semi-elliptical groove 221 and the T-shaped antimony sheet 30, and the first hollow hole 33 and the second hollow hole 34 are respectively located on both sides of the antimony block 32.

[0032] A semi-ellipse is a structure obtained by cutting an ellipse into two halves along the long axis. Compared with an arc, the remaining gradient section 222 has higher stability.

[0033] In a single arc-extinguishing grid 22 , the first hollow hole 33 outside the first semi-elliptical groove 221 is arranged opposite to the second hollow hole 34 outside the second semi-elliptical groove 221 , and the second hollow hole 34 outside the first semi-elliptical groove 221 is arranged opposite to the first hollow hole 33 outside the second semi-elliptical groove 221 .

[0034] The area of ​​the first hollow hole 33 is not equal to the area of ​​the second hollow hole 34. The ratio of the area of ​​the first hollow hole 33 to the area of ​​the second hollow hole 34 is x, and 1.5≤x≤2.

[0035] The area of ​​the piezoelectric ceramic sheet 1 51 is equal to the area of ​​the piezoelectric ceramic sheet 2 52 and their values ​​are both y. The orthographic projection of the piezoelectric ceramic sheet 1 51 and the orthographic projection of the piezoelectric ceramic sheet 2 52 are partially overlapped, and the overlapping area between the orthographic projection of the piezoelectric ceramic sheet 1 51 and the orthographic projection of the piezoelectric ceramic sheet 2 52 is z, 0.3≤z / y≤0.5.

[0036] The resonant frequency of the piezoelectric ceramic piece 1 51 is not equal to the resonant frequency of the piezoelectric ceramic piece 2 52. The resonant frequency of the piezoelectric ceramic piece 1 51 is 10.5 MHz, and the resonant frequency of the piezoelectric ceramic piece 2 52 is 23.2 MHz.

[0037] The high-voltage circuit breaker device for smart grid also includes a detection module for detecting the current size in the circuit. When the detection module detects that the current size in the circuit reaches the first threshold, the control module starts the piezoelectric ceramic piece 1 51 and the piezoelectric ceramic piece 2 52; when the detection module detects that the current size in the circuit reaches the second threshold (the second threshold is greater than the first threshold), the circuit breaker body 10 trips instantly, and at the same time, if an arc is generated, the arc will be extinguished by the arc extinguishing grid assembly in the arc extinguishing chamber. Generally, in order to prevent unnecessary tripping, the overload current or short-circuit current generally lasts for more than 3s before the trip is initiated. Therefore, the 3s window period is completely sufficient for the piezoelectric ceramic piece 1 51 and the piezoelectric ceramic piece 2 52 to start and work for a period of time, thereby ensuring the accuracy of arc extinguishing.

[0038] Compared with the existing arc-extinguishing grids, the arc-extinguishing grid 22 of the present invention has the property of thermal contraction and cold expansion of metal antimony. When the arc passes through the arc-extinguishing grid 22, a large amount of heat generated will cause the arc-extinguishing grid 22 made of steel sheet to expand and contract, while the T-shaped antimony sheet 30 will shrink and expand on the contrary, and the deformation directions of the two are opposite. In addition, the unique structure of the T-shaped antimony sheet 30 causes distortion in different directions at the T-shaped antimony sheet 30 and the gradient section 222. In addition, the asymmetrically arranged first hollow hole 33 and second hollow hole 34 can produce better elongation and cutting effects on the arc, and the arc extinguishing ability is improved.

[0039] The external vibration brought by the piezoelectric ceramic piece 1 51 and the piezoelectric ceramic piece 2 5 can further promote the two adjacent arc-extinguishing grids 22 to produce better elongation and cutting effects on the arc, thereby further improving the arc-extinguishing effect.

[0040] Example 2

[0041] In order to reduce the influence of the vibration generated by the piezoelectric ceramic sheet 1 51 and the piezoelectric ceramic sheet 2 52 on other areas, a shock absorbing layer 53 is filled between the piezoelectric ceramic sheet 1 51 and the piezoelectric ceramic sheet 2 52 and the circuit breaker body 10. The shock absorbing layer 53 is used to absorb vibration.

[0042] Example 3

[0043] The only difference between this example and Example 1 is that in this example, steel is used to replace metal antimony, that is, the T-shaped antimony sheet 30 is replaced by a T-shaped steel sheet, and the rest is the same.

[0044] Example 4

[0045] The only difference between this example and Example 1 is that in this example, copper is used to replace metal antimony, that is, the T-shaped antimony sheet 30 is replaced by a T-shaped copper sheet, and the rest is the same.

[0046] Example 5

[0047] The difference between this example and the third embodiment is that in this example, the first hollow hole 33 and the second hollow hole 34 are not provided, the entire arc-extinguishing grid 22 is a U-shaped steel sheet, and the rest are the same.

[0048] Example 6

[0049] The difference between this example and the first embodiment is that, in this example, when the arc is extinguished, the piezoelectric ceramic sheet 1 51 and the piezoelectric ceramic sheet 2 52 are not started, and the rest are the same.

[0050] According to the test results of "Arc Extinguishing Performance Characterization Test", see Table 1:

[0051] Table 1

[0052]

[0053]

[0054] It can be seen from Examples 1, 3, and 4 that the thermal expansion and contraction properties of metal antimony, combined with the gradient section 222 of common thermal expansion and contraction properties, have very good arc lengthening and cutting effects due to the different deformations between the two; whereas if the same thermal expansion and contraction materials, such as steel or copper, are used, even if high-frequency vibration is applied, the improvement in the arc extinguishing effect is limited.

[0055] Example 7

[0056] The difference between this example and Example 1 is that in this example, the value of x is different. The test results according to the "Arc Extinguishing Performance Characterization Test" are shown in Table 2:

[0057] Table 2

[0058] x Maximum short-circuit current value (A) P(‰) 1 10860 43 1.2 12670 / 1.5 12980 0 1.7 13730 0 2 13550 0 2.5 12620 / 3 12110 /

[0059] As can be seen from the above, when the area of ​​the first hollow hole 33 is equal to the area of ​​the second hollow hole 34, the arc elongation and cutting effect becomes very poor; at the same time, it is easy to cause flying foxes. x is preferably 1.7.

[0060] Example 8

[0061] The difference between this example and Example 1 is that in this example, the z / y value is different. The test results according to the "Arc Extinguishing Performance Characterization Test" are shown in Table 3:

[0062] Table 3

[0063] z / y Maximum short-circuit current value (A) P(‰) 0 14750 33 0.1 13580 19 0.3 13690 1 0.37 13730 0 0.5 13660 1 0.8 13700 15 1 14270 41

[0064] From the above, it can be seen that z / y has a great influence on whether the flying fox occurs, mainly because the flying fox is easy to occur when the vibration is too dispersed or too concentrated. Preferably, z / y=0.37.

[0065] Example 9

[0066] The difference between this example and Example 1 is that, in this example, the resonance frequency of the piezoelectric ceramic sheet 1 51 is different from the resonance frequency of the piezoelectric ceramic sheet 2 52 . The test results of the arc extinguishing performance characterization test are shown in Table 4:

[0067] Table 4

[0068]

[0069]

[0070] It can be seen from the above that the resonance frequency of the piezoelectric ceramic sheet 1 51 and the resonance frequency of the piezoelectric ceramic sheet 2 52 cannot be equal, and at the same time, they can meet the use requirements at a specific resonance frequency.

[0071] Arc Extinguishing Performance Characterization Test

[0072] When the working voltage is 1500V, the maximum short-circuit current value refers to the current flowing through the arc extinguishing grid assembly in the arc extinguishing chamber (the total number of arc extinguishing grids is controlled to be 13, and the area of ​​each arc extinguishing grid is 25.12cm 2 ) of the short-circuit current, its maximum value.

[0073] The probability of arcing P means that when the short circuit trip occurs at the maximum short-circuit current value, observe whether there is arcing outside the arc extinguishing chamber. If there is arcing outside the arc extinguishing chamber, count it. Repeat the test 1000 times, the probability of arcing P = the total number of times the arcing outside the arc extinguishing chamber / 1000.

[0074] After repeating the short-circuit tripping test 1000 times, observe whether cracks are generated on the surface of the T-shaped antimony sheet 30; if cracks are generated, count the number of cracks s; if the cracks are concentrated in one place and accumulate too much, a disconnected gap will be generated at that place.

[0075] The existing circuit breaker has an operating voltage of 1500V, has no piezoelectric ceramic sheet 1 51 and no piezoelectric ceramic sheet 2 52, has a total of 13 arc-extinguishing grids, and an area of ​​each arc-extinguishing grid is 25.12cm 2 The arc extinguishing grid is a U-shaped steel sheet, the corresponding maximum short-circuit current value is 8510A, and the probability of arcing is P=37‰.

[0076] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high-voltage circuit breaker device for a smart grid, comprising a circuit breaker body (10), wherein an arc extinguishing chamber is arranged inside the circuit breaker body (10), wherein an arc extinguishing grid assembly is arranged inside the arc extinguishing chamber, wherein the arc extinguishing grid assembly comprises a housing (21), and a plurality of arc extinguishing grids (22) installed in the housing (21), wherein the arc extinguishing grids (22) are arranged along the length direction of the housing (21), and wherein: The arc extinguishing grid assembly also includes a piezoelectric ceramic sheet one (51) and a piezoelectric ceramic sheet two (52). The piezoelectric ceramic sheet one (51) and the piezoelectric ceramic sheet two (52) are respectively mounted on two sides of the housing (21). The piezoelectric ceramic sheet one (51) and the piezoelectric ceramic sheet two (52) are both fixedly connected to the outer side wall of the housing (21). The piezoelectric ceramic sheet one (51) and the piezoelectric ceramic sheet two (52) are both arranged parallel to the arc extinguishing grid sheet (22).

2. A high-voltage circuit breaker device for a smart grid according to claim 1, characterized in that: The arc extinguishing grid (22) is a U-shaped structure.

3. A high-voltage circuit breaker device for a smart grid according to claim 1, characterized in that: Semi-elliptical grooves (221) are arranged on both front and rear sides of the arc-extinguishing grid (22); the portion of the arc-extinguishing grid (22) located between the two semi-elliptical grooves (221) is a gradual change section (222); a T-shaped antimony sheet (30) is arranged in the semi-elliptical groove (221); the T-shaped antimony sheet (30) comprises an antimony bar (31) connected to the notch of the semi-elliptical groove (221) as a whole, and an antimony block (32) of a trapezoidal structure; the lower bottom of the antimony block (32) is connected to the antimony bar (31) as a whole, and the upper bottom of the antimony block (32) is connected to the gradual change section (222) as a whole; a first hollow hole (33) and a second hollow hole (34) are formed between the semi-elliptical groove (221) and the T-shaped antimony sheet (30); the first hollow hole (33) and the second hollow hole (34) are respectively located on both sides of the antimony block (32).

4. A high-voltage circuit breaker device for smart grid according to claim 3, characterized in that: In a single arc-extinguishing grid (22), a first hollow hole (33) outside a first semi-elliptical groove (221) and a second hollow hole (34) outside a second semi-elliptical groove (221) are arranged opposite to each other, and the second hollow hole (34) outside the first semi-elliptical groove (221) and the first hollow hole (33) outside the second semi-elliptical groove (221) are arranged opposite to each other.

5. A high-voltage circuit breaker device for smart grid according to claim 3, characterized in that: The area of ​​the first hollow hole (33) is not equal to the area of ​​the second hollow hole (34).

6. A high-voltage circuit breaker device for smart grid according to claim 5, characterized in that: The ratio of the area of ​​the first hollow hole (33) to the area of ​​the second hollow hole (34) is x, and 1.5≤x≤2.

7. A high-voltage circuit breaker device for a smart grid according to claim 1, characterized in that: The area of ​​the piezoelectric ceramic sheet one (51) is equal to the area of ​​the piezoelectric ceramic sheet two (52) and their values ​​are both y, the orthographic projection of the piezoelectric ceramic sheet one (51) and the orthographic projection of the piezoelectric ceramic sheet two (52) are partially overlapped, and the overlapping area between the orthographic projection of the piezoelectric ceramic sheet one (51) and the orthographic projection of the piezoelectric ceramic sheet two (52) is z, 0.3≤z / y≤0.

5.

8. A high-voltage circuit breaker device for a smart grid according to claim 1, characterized in that: The resonant frequency of the piezoelectric ceramic plate 1 (51) is not equal to the resonant frequency of the piezoelectric ceramic plate 2 (52).

9. A high-voltage circuit breaker device for a smart grid according to claim 8, characterized in that: The resonant frequency of the piezoelectric ceramic plate 1 (51) is 10.5 MHz, and the resonant frequency of the piezoelectric ceramic plate 2 (52) is 23.2 MHz.

10. A high-voltage circuit breaker device for a smart grid according to claim 1, characterized in that: A shock-absorbing layer (53) is filled between the first piezoelectric ceramic sheet (51) and the second piezoelectric ceramic sheet (52) and the circuit breaker body (10).

Images